As you can see, the rovers arm does not have any cables flapping about in the wind - even if it came undone, it is unlikely to come undone ALL along its length, as the real one is a ribbon cable attached firmly at regular intervals all along the inside edge of the arm.

qmantoo wrote:From 2191 onwards to 2208, there is nothing but a couple of black square/white spot for each day. Lets hope it is only a glitch and nothing permanent.

That's the sun, not a glitch. The PanCam has a solar filter and takes pictures of the sun periodically to aid in navigation and to make measurements of the attenuation of the atmosphere.

You can find these small subframe solar images throughout the lifetime of both rovers, usually every few days. Notice that every one of these images uses Filter #8, and no other images use that filter.

Actually, I was being a little sarcastic because I thought that this was the reason the NASA guys would give if the footprint diminished like the Phoenix one did.

What other reasons could they come up with? Maybe we help them dream up some designer-reasons why the solar panels might 'fall off' of Spirit after the Martian winter is over. Anyone give prizes for the best concocted reason?

Now we just have to wait for the winter snows to fall and put so much weight on the solar panels that they collapse and all hope of recovery of the situation is lost. Similar to Phoenix really.

Both rovers are in relatively equatorial regions (2 degrees S and 15 degrees S) where there is no accumulation of frozen material during winter. They have both survived multiple Martian winters and Spirit is right now heading out of winter and into spring.

There is no danger of the solar panels collapsing from frozen material.

Phoenix landed at 68 deg N, well into the polar region where it is assured that the solar panels were covered in frozen material during its winter.

But, there's a further risk, said [John] Callas [project manager for Spirit and Opportunity at NASA's Jet Propulsion Laboratory]

"The rover may also experience a mission-clock fault," Callas said. "It's like when you turn your hair dryer on and the lights blink momentarily. As the rover actually starts to wake up, and the heaters and loads come on, this could cause the clock to reset, and if that happens, the rover loses track of absolute time."

That would be unfortunate. If Spirit loses track of time, it could stretch its hibernation time out to its maximum – if it survives the Martian winter at all. Callas' expectation is that Spirit will not wake up for several months.

If the rover has experienced a low power fault, he estimates Spirit could wake in late September or early October. But, if Spirit has experienced a mission-clock fault, the rover may not come out of hibernation until November.

"If we can have the rover respond to us, we can at least have a sense of timing," Callas said. "When your alarm clock loses track of time, you can go in and reset it. We would do the same thing with Spirit once we're able to communicate regularly with the rover."

On July 26, NASA's Mars rover team began using a paging technique called "sweep and beep," in which commands are sent repeatedly to the rover to check if it is awake and listening.

"Instead of just listening, we send commands to the rover to respond back to us with a communications beep," Callas explained. "If the rover is awake and hears us, she will send us that beep."

If the charge in the batteries drops below the operational threshold the internal electronic master clock will stop - end of story. the operational threshold can only be maintained if charge current is provided by the solar cells.

what happens to your video, tv or DVD player if you remove the mains plug from the socket on the wall?

Your answer draws on your analogy between consumer electronics and not on any actual references to the rovers' design.

Use this analogy instead. Unplug a computer from the wall. Remove all its internal backup batteries. Now plug it back into the wall (the equivalent of the solar panels charging the batteries to a particular voltage level, easily accomplished through analog electronics that do not require the computer to be running). Many computers have settings that will autmatically reboot the computer when power returns after a power outage. The computer reboots and then can automatically run software from the Startup folder for example. My computer in a case like this will tell me "The clock has been reset to Jan 1, 1904" but will still run perfectly fine. It then listens until it receives a wireless signal and syncs up its clock to the server.

The rover does something similar to this (according to my references). When the battereis are sufficiently charged from the solar panels, the computer reboots and starts running software specifically designed to recover from a mission clock fault. The rover listens for a signal from Earth or from one of the orbiters.

what happens to your video, tv or DVD player if you remove the mains plug from the socket on the wall?Eventually the little button battery cell inside which keeps the timer chip and processor going will fail and everything will stop. Most computers have a small button battery cell to keep the clock going. If you take that out, the clock will stop and when power is restored it will reset itself to zero. However, it is quite possible that after x seconds after power is restored very basic things start to work on the rover - possibly enough to get a time signal from the orbiter perhaps?

Now we just have to wait for the winter snows to fall and put so much weight on the solar panels that they collapse and all hope of recovery of the situation is lost. Similar to Phoenix really.

***It is strange how all these beings can survive such harsh winters - where are all the deep burrows and underground bases etc? How come we can see so much evidence above ground of civilisations? Their heating and air conditioning systems must be really really good !!***

Anyone who believes that there are civilisations on Mars, cannot believe the story about the weather. The two things seem to contradict each other as I have pointed out above. I just wonder how far underground you would have to tunnel to escape from such harsh temperatures as we are told exist.

I suppose these aliens - if they exist - could have totally different biology and cell structure so that they can survive in minus 40C temperatures. I am not an alien biologist so I dont know. All I can do is wonder....

However after all this, I do not see much evidence of freeze/thaw mechanics on the rocks like we have here on Earth, as we all know that continuous freeze/thaw cracks rocks and eventually they disintergrate.

Where is the evidence?

I am still waiting for weathering evidence from these large sand storms and dust devils which Software Pyrate will be providing me with...

If the charge in the batteries drops below the operational threshold the internal electronic master clock will stop - end of story. the operational threshold can only be maintained if charge current is provided by the solar cells.

what happens to your video, tv or DVD player if you remove the mains plug from the socket on the wall?

__________________

"All truth passes through three stages. First, it is ridiculed; Second, it is violently opposed; Third, it is accepted as being self-evident."

"That is not true. A mission clock fault would not, in itself, end the mission."

I'm sorry OBrien, I disagree. Without the master clock pulses being generated, everything would stop even though the batteries may still hold a reasonable charge.

Where Spirit is located at the present time and the orientation of the craft has NASA a little worried. The solar panels are facing away from the light source, therefore the amount of light being captured by the solar panels is drastically reduced. Many of the utilities onboard the craft can be either switched off or put into a stand-by state. But, if the batteries were to fail altogether or reach a state where there was insufficient charge this could render the master clock inoperative and synchronization within the system would be lost. Without a clock everything stops.

__________________

"All truth passes through three stages. First, it is ridiculed; Second, it is violently opposed; Third, it is accepted as being self-evident."

The spirit mission as well as the opportunity mission are both a fiasco.

If you take a close look at Victoria crater the rim is separated from the basin. So there's no way little carts could have walked down the slope as they wanted us to believe. (See 3D analysis of its tophology)

Maybe they are limiting the effectiveness of the camera devices to conserve energy to keep the master clock operational. Without the master clock pulses being generated everything would stop and that would be the end of the mission.

That is not true. A mission clock fault would not, in itself, end the mission.

From a July 30, 2010 press release:

WASHINGTON, July 30 /PRNewswire-USNewswire/ -- NASA mission controllers have not heard from the Mars Exploration Rover Spirit since March 22, and the rover is facing its toughest challenge yet ? trying to survive the harsh Martian winter.

The rover team anticipated Spirit would go into a low-power "hibernation" mode since the rover was not able to get to a favorable slope for its fourth Martian winter, which runs from May through November. The low angle of sunlight during these months limits the power generated from the rover's solar panels. During hibernation, the rover suspends communications and other activities so available energy can be used to recharge and heat batteries, and to keep the mission clock running.

On July 26, mission managers began using a paging technique called "sweep and beep" in an effort to communicate with Spirit.

"Instead of just listening, we send commands to the rover to respond back to us with a communications beep," said John Callas, project manager for Spirit and Opportunity at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "If the rover is awake and hears us, she will send us that beep."

Based on models of Mars' weather and its effect on available power, mission managers believe that if Spirit responds, it most likely will be in the next few months. However, there is a very distinct possibility Spirit may never respond.

"It will be the miracle from Mars if our beloved rover phones home," said Doug McCuistion, director of NASA's Mars Exploration Program in Washington. "It's never faced this type of severe condition before ... this is unknown territory."

Because most of the rover's heaters were not being powered this winter, Spirit is likely experiencing its coldest internal temperatures yet -- minus 67 degrees Fahrenheit. During three previous Martian winters, Spirit communicated about once or twice a week with Earth and used its heaters to stay warm while parked on a sun-facing slope for the winter. As a result, the heaters were able to keep internal temperatures above minus 40 degrees Fahrenheit.

Spirit is designed to wake up from its hibernation and communicate with Earth when its battery charge is adequate. But if the batteries have lost too much power, Spirit's clock may stop and lose track of time. The rover could still reawaken, but it would not know the time of day, a situation called a "mission-clock fault." Spirit would start a new timer to wake up every four hours and listen for a signal from Earth for 20 minutes of every hour while the sun is up.

The earliest date the rover could generate enough power to send a beep to Earth was calculated to be around July 23. However, mission managers don't anticipate the batteries will charge adequately until late September to mid-October. It may be even later if the rover is in a mission-clock fault mode. If Spirit does wake up, mission managers will do a complete health check on the rover's instruments and electronics.

Based on previous Martian winters, the rover team anticipates the increasing haziness in the sky over Spirit will offset longer daylight for the next two months. The amount of solar energy available to Spirit then will increase until the southern Mars summer solstice in March 2011. If we haven't heard from it by March, it is unlikely that we will ever hear from it.

Maybe they are limiting the effectiveness of the camera devices to conserve energy to keep the master clock operational. Without the master clock pulses being generated everything would stop and that would be the end of the mission.

__________________

"All truth passes through three stages. First, it is ridiculed; Second, it is violently opposed; Third, it is accepted as being self-evident."

Just a hunch... that they may have got (dismantled or disabled) the pancam.

From 2191 onwards to 2208, there is nothing but a couple of black square/white spot for each day. Lets hope it is only a glitch and nothing permanent. It would be nice to see some more terrain from the pancam, just to make sure it is still there.

Maybe they just got fed up with taking pictures of the same boring panorama?

sorry, I was not meaning that there was something missing from the arm itself or the shadow of the arm, only that there are rows of somethings which have been blacked out by the arm's "shadow" and the shadow in the bottom right hand corner. There is nothing to cast a 'V' shaped shadow there.

Also I suspect there is something going on on the left edge semi-circular shadow.

Thank you for the picture of the rovers arm and shadow but it does not show the area where I think there may be activity. If there is activity and what I suspect is true (however bizarre it may be!), it is doubtful whether we will get more images of this area again.